On Monday night The Tanks were thrumming with smoke and lasers and ram-packed with people, like in a 1990s Berlin disco. I don’t often go to an opening at Tate, but I do go to a lot of performances, and this number of people is unusual for the latter context, if not the former. This could mean a number of things: that performance is ‘in’, perhaps, or that Tate can attract punters to the opening of a jam jar. These are the most obvious and cynical responses, but a more thoughtful one would likely involve a discussion of, amongst other things, experience and display in culture and commerce, interdisciplinarity in a diversified society and the psychology of time. I am imagining that the coming months’ programme of performance and installations will allow the time, space and content to think about these issues in depth, but for now, for me, the immediate considerations are magnitude and endeavour, because above all else, the Tanks are so huge and the human body so small.

You couldn’t really call this sort of functional architecture ‘brutalist’, since this label implies aesthetic decisions made for affect, but the concrete facets, which have been left in their rough, or some might say ‘honest’ state, really press home not just the vulnerability of the flesh but also the extent of certain impressive collective and sustained efforts. These tanks were originally full of oil, and this oil may well have been drilled out of the torrid North Sea or brought halfway round the world from Iraq or Nigeria.

I often wonder why I am so interested in performance. So much of it is terrible (we can say this – even the most liberal have bench marks and yard sticks) and the vast swathes of gallery goers who find it embarrassing are often quite justified in saying so – it is a particularly undisciplined discipline. But while watching the incredible virtuoso movements of Anne Teresa de Kaersmaeker it occurred to me that performance produces the illusion that we are watching an endeavour as it is being undertaken. While an art object arrives fully formed, a performance displays some of the effort of its own making (although there is much preparation and rehearsal that remains hidden). This visibility of process means that there is still an opportunity for something to go wrong, which is what makes some people unenjoyably tense; but it also piques a keener sense of triumph when it goes right. They did that right then right here. This tension within liveness is sometimes described as ‘authenticity’, but this is a near-meaningless term, since every act is mediated to some degree. But liveness does court failure quite markedly, and this is the relief that it offers from ‘reality’. We try to avoid completely the impact of failure in, say, job seeking, oil drilling, mental arithmetic and so on, but the fact that a performance has no outcome other than itself, nothing to ruin but the audience’s evening (although this would be difficult, since a bad performance makes for better conversation), means that we can give some attention to the tension within effort itself. This tension has its own aesthetics, which a good performer will use as a medium, as much they would a musical instrument or their body. They invite admiration of their ability to invent, control and persist – for to spend months devising a very particular way of jumping up on to your toes really is quite strange and wonderful.

It is often assumed that performance art is automatically politicised – due partly to its prominence in feminist art and partly to claims of radical anti-capitalist dematerialisation. This is not always the case these days, as many artists have a more formal agenda or might be on a blue-chip career path. But I think that there is something about the live act that is innately critical, if viewed from a certain angle. If we are shown, even partly, how something has come about, and have albeit a fleeting glimpse of the efforts involved, then the twin cultures of entitlement and blame might crumble just a little. The unquestioning acceptance of things precisely as they are is a brittle state of ignorance, and so, while I’m sure many artists working with performance are not on such an ethical crusade, the live event reminds us, in microcosm, of the precarious nature of everything.

Sally O’Reilly is a writer and curator. She is the author of ‘The Body in Contemporary Art’ and is currently writing a novel, ‘Crude’, about art, flirting and the oil industry.